I think people should literally never bring a young puppy to a dog park and most of the times its rather dangerous to bring a full grown dog too.
Please read the following article for reasons as to why the dog parks are so dangerous
Why dog parks are dangerous
This is one of those random dog training tips. 
For best results a dog should have the following things when being trained:
- Fun
- Attention on his/her owner
- Consistent owner who makes same decisions everytime
- An owner who doesnt lose temper at his/her dog
- A good system of positive reinforcement. Mix it up, dont always give a dog a treat, make the dog guess
- Make the dog training sessions no longer then 30-60 min depending on the dog. Dogs get bored fast just like children
- An understanding owner who knows the dog in and out
Follow the above advice and you’ll have much happier dog training experience.
More random dog training tips will be added in the future. 